I don't think it's a secret I'm framing it as a glamour request, given that I thought I was kicking off a discussion about what potential designs could be used if it was implemented, not defending the concept itself!
And while I did say "relic gear" in the title, it's more like shorthand for "repurposing existing designs to be used as a functional equivalent to relic gear". It seems on par with going back to add gunblades and chakrams to all the Lv60-70 dungeons when those jobs were implemented, which happens routinely - it falls within the levelling range of those jobs, so equivalent gear is added for them.
As for just fully unrestricting gear sets like they did for the Sky Pirate sets, sure, I'd prefer that too - but I feel like that just isn't going to happen for everything. It seems clear to me from the way they approach recycled gear designs that there are some designs that they're happy to "share around" and give to a different class each time they appear, and some designs that are strictly role-based and won't ever vary. Even shared designs tend to stick between only going between healers/DPS for lighter designs and DPS/tank for heavier, rarely crossing over all three roles (though there are occasional exceptions).
The Dravanian designs, for example, have appeared three times now (Lv55 Orthodox, Lv60 Dravanian, Lv64 crafted) and have gone to the same roles each time. So have the World of Darkness designs (Lv50 Demon, Lv70 crafted, Lv79 Forgiven). The mage robes are very "magey", the tank armour is "knightly" and the DPS gear suits a lightweight physical fighter. If you went to someone who has never played an RPG in their life and showed them pictures of those outfits, they would be able to identify the character archetypes that would wear them.
The Sky Pirate sets have no such affinity to their roles, and that - I believe - made them much better candidates for being freed up as replicas.
But even if, as I assume, they are unlikely to free up the whole set of Dravanian designs, the more targeted scenario of giving only the DPS set to only red mage would be a different level of consideration. It's not letting tanks wear the robes or mages wear the heavy armour, it's just saying this one outfit would work for this specific job, and there's an opening to make that available.
All that said, I do honestly think there is a gameplay benefit to implementing these equal-to-relic sets, and I'm pretty sure that's what started me off thinking about the glamour potential. I didn't set off thinking "how can I wedge in a glamour request?" but seeing as there is a gear gap that needs filling, then it's a missed opportunity to not fill it with glamour.
It's certainly a stopgap, but it still is a gap that could do with a stop.
From my own recent experience I got a character through Stormblood recently - mainly playing AST/DNC with DNC being his main story class. At Lv70, other classes would (or at least can) get free Lv70 gear prior to the Ala Mhigo dungeon, but if I wanted to be equally prepared then I had to go buy that for myself.
And even after clearing, you can't buy a whole gearset-worth of Scaevan gear with 2000 poetics, let alone two, so for AST I had the relic gear to fill in the gaps until I could save up more. I couldn't do that for DNC, even if I made it my priority for gearing.
The MSQ does eventually give you one full set of i360 poetics gear - from memory: accessories immediately, weapon at the end of 5.1 and left-side gear not until the end of 5.2. Until then, you're at a disadvantage.
I would imagine if they hypothetically did this, it would follow the same variations as the relic gear it is matching: undyeable i90, dyeable i210, antiquated i290 with Anemos upgrade (boo hiss).
And yeah, unique patterns are another opportunity - like the dancer version of the Thavnairian set having a different pattern to the standard version. Which they sort of had to do, because it was a bit of a letdown using gear that was already freely available to be used for the job.